Revert of Small refactor around futex.h.

Revert of Small refactor around futex.h. (patchset #1 id:20001 of https://codereview.chromium.org/1076213002/)

Reason for revert:
Breaks ChromeOS veyron_jerry boot.

BUG=477352
Original issue's description:
> Small refactor around futex.h.
>
> This is the preparation of seccomp-bpf implementation
> for nacl_helper_nonsfi.
> PNaCl toolchain does not provides linux/futex.h.
> This CL is the preparation to reuse android_futex.h
> for PNaCl toolchain, too.
>
> TEST=Ran bots.
> BUG=358465
>
> Committed: https://crrev.com/3b996212fa3c92af3233246ae54af728eb7c3591
> Cr-Commit-Position: refs/heads/master@{#324996}

TBR=mdempsky@chromium.org,hidehiko@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=358465
Committed: https://crrev.com/4c05c94295ee26adffe966678719085f02b15f2f
Cr-Commit-Position: refs/heads/master@{#325265}

[dnicoara, 2015-04-15 17:22:27]

Created Revert of Small refactor around futex.h.

[commit-bot: I haz the power, 2015-04-15 17:23:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1084173003/1

[commit-bot: I haz the power, 2015-04-15 17:25:14]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-15 17:26:09]

Patchset 1 (id:??) landed as
https://crrev.com/4c05c94295ee26adffe966678719085f02b15f2f
Cr-Commit-Position: refs/heads/master@{#325265}

[dnicoara, 2015-04-15 17:42:04]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1088253002/ by dnicoara@chromium.org.

The reason for reverting is: Sorry, mistake on my part, this CL isn't the
cause..